[APWG] [RWG] Ecosystem Restoration Collapse

Tue Feb 28 06:35:30 CST 2012

Just to clarify, ecosystems are dynamic and constantly changing, but not at
the present rate of change. When endangered species were protected with
national and international laws and programs several decades ago, we agreed
that species naturally become extinct over time. It is just the rate of
extintion that had increased a thousand fold and needed to be reversed so
new species had an ecosystem to evolve in. 

Marc Imlay, PhD, 

Conservation biologist, Park Ranger Office

(301) 442-5657 cell

 ialm at erols.com

Natural and Historical Resources Division

The Maryland-National Capital Park and Planning Commission

www.pgparks.com <http://www.pgparks.com/> 

  _____  

From: apwg-bounces at lists.plantconservation.org
[mailto:apwg-bounces at lists.plantconservation.org] On Behalf Of
Hempy-Mayer,Kara L (CONTR) - KEC-4
Sent: Monday, February 27, 2012 2:14 PM
To: 'apwg at lists.plantconservation.org'
Cc: 'rwg at lists.plantconservation.org'
Subject: Re: [APWG] [RWG] Ecosystem Restoration Collapse

Agreed.  I've heard many people argue against the ideas of "ecosystem
preservation" and "restoration," but it's usually a matter of semantics.
What restoration and preservation are trying to accomplish is to maintain
diversity on a global scale: there are ecosystems here that worked well
before we starting impacting them so profoundly: we attempt to "restore"
them by taking out what we put in (exotic weeds), or trying to repair what
we damaged (soil structure, hydrology, etc.).  Then, hopefully, the previous
ecosystem processes can reestablish.

As to the argument about increased carbon dioxide levels: I've always
wondered about this.  The argument that increased CO2 in the atmosphere has
a profound effect on plant growth assumes that nothing else is limiting
plant growth. From my limited background in plant physiology, there are
usually many things limiting plant growth: macronutrients, micronutrients,
water, and light.  In balance, can CO2 have that big of an effect, even if
it is limiting? Are there field studies that have found evidence for this?

Thank you for the opportunity to comment -Kara

From: apwg-bounces at lists.plantconservation.org
[mailto:apwg-bounces at lists.plantconservation.org] On Behalf Of William
Stringer
Sent: Monday, February 27, 2012 8:41 AM
To: Robert Layton Beyfuss; Katie Fite; Wayne Tyson
Cc: apwg at lists.plantconservation.org; rwg at lists.plantconservation.org
Subject: Re: [APWG] [RWG] Ecosystem Restoration Collapse

As to ecosystem restoration , we are not proposing to make a man-made Hope
Diamond here.  We are proposing to work from our admittedly limited
knowledge base of what should be there, and what should not.  We take out,
to the degree that we can, the should-nots, particularly the known exotic
invasive should-nots.  We then try to place into the site local-source
propagules of known natives in a patchwork of mixtures of relatively
compatible species.  At that point we have probably done most of what we can
contribute.  We can manage the site to the degree that we can simulate
natural disturbance phenomena.  But mostly at this point we stay out of the
way and let natural phenomena drive the restoration.  The only exception
would be if outbreaks of exotic invasive species begin to threaten.  Then,
we monitor and learn

What we cannot do is let micro-analysis of the term restoration immobilize
us into total inaction.

Bill Stringer

  _____  

From: apwg-bounces at lists.plantconservation.org
[apwg-bounces at lists.plantconservation.org] On Behalf Of Robert Layton
Beyfuss [rlb14 at cornell.edu]
Sent: Monday, February 27, 2012 10:26 AM
To: Katie Fite; Wayne Tyson
Cc: apwg at lists.plantconservation.org; rwg at lists.plantconservation.org
Subject: Re: [APWG] [RWG] Ecosystem Restoration Collapse

I do not understand how ecosystems can be restored since I consider them as
dynamic and constantly changing. It is not possible to completely re-create
the environmental conditions that led to a given ecosystem at any given time
in the past. If ecosystems represent the interactions of living and
environmental factors, to restore an ecosystem requires replicating the
previous environmental factors that affect the living organisms. The level
of carbon dioxide in our atmosphere has doubled in the past 80 years. Plant
growth, reproduction and survival is profoundly affected by carbon dioxide
levels. I consider attempts to restore ecosystems  as  no more than human's
creating new ecosystems using species of plants that previously occurred
because humans liked the previous once more than the current one.    

From: apwg-bounces at lists.plantconservation.org
[mailto:apwg-bounces at lists.plantconservation.org] On Behalf Of Katie Fite
Sent: Monday, February 27, 2012 9:12 AM
To: Wayne Tyson
Cc: apwg at lists.plantconservation.org; rwg at lists.plantconservation.org
Subject: Re: [APWG] [RWG] Ecosystem Restoration Collapse

Wayne,

I am interested in the discussion.

And discussions of what ecological restoration is, and also discussions of
how the term "restoration" is currently being used by agencies or at times
industry  -  to describe imposing major disturbances on mature or old growth
woody vegetation communities  - with such disturbances often then leading to
weed invasions.

Katie Fite

On Sat, Feb 25, 2012 at 8:33 PM, Wayne Tyson <landrest at cox.net> wrote:

All:

One of my fellow subscribers has been corresponding with me off-list the
subject of ecosystem restoration standards, and I have been unsuccessful in
persuading the subscriber to keep the discussion on-list, as I believe the
subject is of broad common interest. This person apparently believes that I
am the only one (with one or two others) interested, because no one else has
weighed in on the subject. Is this person right? Are none but three or four
of us interested in this topic? Should this and related topics be kept off
list (to keep topics of restricted interest from clogging the in-baskets of
the majority? If so, how many subscribers are there to APWG and RWG? 

I am hereby taking the liberty to broach the most recent topic, the collapse
of ecosystem restoration projects, signified by the return of weed dominance
in some cases. I would add to this that ecosystem restoration projects also
"collapse" or fail to "take" whether or not weeds dominate. The off-list
poster confined the comments to grasslands, so I will primarily address that
issue, but the same principles hold true for other biomes and can be more
broadly applied. 

First, the "return" of grassland restoration projects to weed-dominance. 

There are a number of reasons for this, some related to context issues like
soil type, some related to restoration methods, but consideration of soil
type must be part of the restoration assessment, planning, and execution
process. Soil type is important; in the case of grassland restoration, it is
preferable (actually essential) that a grassland soil is present--if it
isn't, all the King of Restoration's horses and all the KoR's men and women
will not be able to make a silk purse out of a sow's ear (without some major
alterations to the soil). I invite others to expand and expound on this
subject; I will mention only some factors. 

True grassland soils tend to have identifiable characteristics. They tend to
develop on alluvial or aeolian soils of finer texture and containing
considerable natural humus and soil flora/fauna, as well as mineral deposits
at depth (commonly at or near the effective bottom of the root zone) such as
calcium and sodium. Disturbance of such soils can render the site largely
incapable of supporting a true grassland, such as when bulldozed or
otherwise excavated and the surface is changed from a grassland-type soil to
a jumbled mass, sometimes consisting of coarse B-horizon or deeper deposits
unsuited to grassland development. This should be determined in the initial
assessment and feasibility investigation, and consideration should be given
to restoring an ecosystem/plant community type other than grasslands, at
least as a transitional measure until something resembling a grassland soil
can be developed. (Wholesale replacement of the degraded soil with grassland
soil can be done, but it is terribly expensive.) 

If one tries to establish a grassland on non-grassland soils, one is most
likely going to be disappointed, and "failure" is almost foreordained. I
have, however, attempted to grow hair on such billiard-ball sites, with
limited success. If other conditions are favorable, a soil can sometimes be
developed (or its development accelerated) by certain tricks (e.g., praying
for gopher or prairie-dog invasions, adding mycorrhizal fungi and other
essential soil organisms, and transitional plantings of annual
plants--sometimes even grasses, but more commonly dicots like weeds and
flowers that will be humus-builders. Short-lived perennial plants, even some
shrubs, also can be used. This approach is much cheaper than soil
importation, and sometimes can be better. The actual strategy should fit the
context. 

I should make it clear that my first fifteen years of attempting ecosystem
restoration projects were all failures by my own standards, and I have
continued to make some mistakes once ever since. One must, I believe, learn
from actual experience. However, just experience is no guarantee of
expertise. If I had stubbornly held on to what I "knew" and refused to
consider that what I knew might be wrong, I would have continued to fail. I
did get to the point that could reliably initiate ecosystem processes and
avoid "collapse." All restoration practitioners can do is to accelerate
ecosystem development anyway, largely by setting up conditions that will
permit or even maybe encourage natural ecosystems processes to work. We
don't actually restore living systems. 

In short, most failures can be traced back to the kind of work done and not
done to set up favorable conditions for natural forces to work upon. 

In short, two of my biggest mistakes (there have been many others) have been
to: 

a. fail to properly assess site conditions and develop a restoration program
that modifies or matches those conditions. 

b. plant too many seeds and plants, spending far too much money and doing
far too much presumptuous guesswork. 

If a grassland soil is present, indigenous species can persist and
eventually re-assert dominance over weed populations. If one can mimic
grassland soils, one has a chance of fostering the development of grassland,
but one must out-draw the Lone Ranger to do it. If one is presumptuous
enough to believe that all that needs to be done is to kill weeds and
scatter seeds, collapse, unless one is terribly lucky, is rather more likely
than not. 

Disturbed sites (from bulldozing to trampling) tend to favor weeds. They are
the scabs, as it were, on the scarred face of the earth--not pretty, but an
inevitable result of land mismanagement. 

2. Collapse of "restored" ecosystems that do not necessarily result in
dominance of weeds.

This phenomenon is often the result of simply seeding or planting too many
and/or the wrong balance of the right (and/or wrong) species at the wrong
time, possibly including "maintenance." 

This can be the subject of another discussion, but I have run out of time .
. . (and since it does not include weeds so much, it might be
"inappropriate" for these lists. 

WT

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